By 2020 to 2025 we will have the resolution, speed, bandwidth to scan the entire human brain. A $1,000 computer will match the processing power of the human brain - about 20 billion calculations per second.

By the 2030s, people will be able to download their brains into a computer and create a self-replica. This process will be called "reinstantiation."

How seriously should we take Mr. Kurzweil and his predictions? Very.

Kurzweil is not given to hype. He has a proven track record of assessing technological change in discrete time frames and then determining what is likely to occur coincidental with the increase in the processing power of microchips.

In his previous book, "The Age of Intelligent Machines" (MIT Press, 1990), he predicted a worldwide information network linking almost all organizations and tens of millions of individuals: the World Wide Web; defeat of the human world chess champion by a computer by the year 1998; the vast majority of commercial music created on computer-based synthesizers; and almost total reliance on digital image pattern recognition and other software-based technologies in warfare.

In the past 25 years, the Massachusetts Institute of Technology graduate founded, built, and sold, four companies. His first company, Kurzweil Computer Products, created a reading machine for the blind. He sold it to Xerox. The musician Stevie Wonder was one of his first customers. A bond between the two of them led to the development of music synthesizers.

Wall Street certainly takes him seriously. His current project is a software program for fund managers creating an artificially intelligent financial analyst that outperforms humans "by taking advantage of certain arbitrage opportunities," he says. Growth in this form of financial transaction is going to be "huge." Around $5 billion now, it will quickly grow into hundreds of billions of dollars.

Kurzweil possesses a highly refined and precise ability to think exponentially about technology over time. His perception of how things are likely to change comes as naturally to him as balancing a checkbook does to an accountant.

A practical dreamer

Substitute the term co-processing - multiple tasks occurring simultaneously - for conversation, and you get a sense of what it's like to talk with him. He makes so many connections in so many scientific disciplines on matters so fundamental to what it means to be a thinking being that the implications confront the mind like an air, sea, and land assault.

This is not to suggest an interview with Kurzweil at his office in Waltham, Mass., is an encounter with a Prussian officer. Passion, insight, nuance, vision, and a gifted teacher's grace to listen to each student, characterize an exchange with him.

"By 2029, we will have the ability to scan someone's brain, and record every salient detail relevant to its processing of information. We can then re-create those precise processes in a neural computer of sufficient capacity," he says. As shocking as the concept is, his calm, assured prediction of what it will lead to makes the whole endeavor sound less threatening.

By 2040, he says, "this will be a routine occurrence." Such a prediction is by far the most provocative, some would say the most controversial, in his latest book, "The Age of Spiritual Machines: When Computers Exceed Human Intelligence."

And then? "That person, or at least a very good copy, will emerge in the machine. That person will claim to be the original person. He will think that he was the original person, having lived a certain life and then having woken up in the machine," he says.

"Most of human intelligence is not logical thinking. It is something called pattern recognition," he says, "which is a self-organizing process where we have millions of little processes and they interact and the solution emerges from the unpredictable interplay of millions of little processes. We can build our machines with similar qualities, not based on rules, but based on self-organizing processes that emulate what we understand about the human brain."

Kurzweil acknowledges that some people who have read his book come away feeling depressed. He pauses, making sure he is perfectly clear about what it is he predicts.

"We will meet nonbiological entities in the 21st century that will claim to be human, that will claim to be conscious, that will claim to have feelings, and claim to have emotions. And when they make these claims they will act in appropriate ways that will be very convincing and compelling in those claims. And included in that will be claims to have spiritual experiences, just the way humans claim to have spiritual experiences. And their behavior in terms of transcendent type of behavior ... rapture, will also be very convincing and compelling," he says.

It will get really interesting when they start designing their own bodies, he adds.

"Are they really having spiritual experiences, are they conscious?" he rhetorically asks. "I don't give a simple answer to that in the book. I talk about a 2,000-year-old perspective on that and show that each of these perspectives has contradictions."

Who defines consciousness?

So how, or even will, we settle the issue of conscious machines?

"We'll settle it politically," he says. The behavior of these entities will be so compelling and convincing, they'll, in effect, ultimately be smarter than humans are today, so they'll succeed in convincing people that they are conscious, that their feelings are genuine.

"We are not evolved to deal with very rapid change. We evolved slowly," he says. "Technology is inherently an accelerating phenomena." On the subject of evolution, Kurzweil often sounds like a philosopher. His principle is that being, life, is directed toward a definite end and has an ultimate purpose.

"Evolution works towards great order," he says. "It's just that technology has taken the lead." Remember he says, the research and development of artificial intelligence going on right now is "very decentralized [and] that has a very positive effect.

"Order is even more profound than information. It is information that fits a purpose. It is a step toward information that is more profound, more beautiful, more inspiring, [even though] evolution is a seemingly random swirl of events. It moves towards indescribable beauty, intelligence, and creativity - all the things that God has been called."

"The technologies of the 21st century will create a very wealthy and profound future where we can overcome humanity's unmet material needs and expand our creative horizons," he says.

"Go where your passions are," concludes Kurzweil. It would be a big mistake for a budding musician to study computer science. "Discover how you can contribute to this dialogue of creating something with your intellect and follow that."